convert policy item to string label (stolostron#4014)

Signed-off-by: Randy Bruno Piverger <rbrunopi@redhat.com>

Author: Randy424

frontend/src/routes/Governance/policies/Policies.tsx

@@ -228,7 +228,11 @@ export default function PoliciesPage() {
         isDefault: false,
         isFirstVisitChecked: true,
         exportContent: (item) => {
-          return item.source ?? '-'
+          let type = item.source ? item.source : '-'
+          if (typeof item.source === 'object') {
+            type = getResourceLabel(item.source.props?.appRepos[0]?.type?.toLowerCase() ?? '', 1, t)
+          }
+          return type
         },
       },
       {